/Engine/Plugins/FX/Niagara/Source/Niagara/Public/NiagaraFunctionLibrary.h
static bool DefineFunctionHLSL ( const [FNiagaraFunctionSignature](API\Plugins\Niagara\FNiagaraFunctionSignature) & FunctionSignature, [FString](API\Runtime\Core\Containers\FString) & HlslOutput )